POLYNOMIAL REPRESENTATION OF DIFFRACTION FIELDS AT CRUSTAL IRREGULARITIES.

Abstract

By means of the Lanczos tau method, polynomial representations are found for the transverse variation of modal solutions of the wave equation. This limits the transverse variation to a finite number of degrees of freedom. While restricted to a finite number, the accuracy in representing modal variation is highly satisfactory, particularly for the lower order modes. Furthermore, major computational advantages materialize in the succeeding analysis. Contour integral representations of solutions of the approximate wave equation no longer involve branch cut integrations-- the only singularity being a family of poles at plus or minus k where k is the propagation constant within the waveguide. Accordingly, Weiner-Hopf problems can be solved almost by inspection inasmuch as the kernel to be factored is a rational function with explicitly displayed poles and zeros. Explicit formulas are given for the entries in the scattering matrix that describes the junction of two dissimilar waveguides. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 15, 1969
Accession Number
AD0689436

Entities

People

  • Eugene Denman
  • Julius Kane
  • Tapendra Nath Maulik

Organizations

  • University of Southern California

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Contour Integrals
  • Diffraction
  • Equations
  • Inspection
  • Integrals
  • Mathematics
  • Polynomials
  • Rational Functions
  • Scattering
  • Transverse
  • Wave Equations
  • Waveguides

Readers

  • Approximation Theory.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Microwave Engineering.